erent from its predecessor, is seen to be an inherent and, _ex
hypothesi_, necessarily disturbing factor in all habitual action--and the
life of an organism should, as has been sufficiently insisted on, be
regarded as the habitual action of a single individual, namely, of the
organism itself, and of its ancestors. This is the key to accumulation
of improvement, whether in the arts which we assiduously practise during
our single life, or in the structures and instincts of successive
generations. The memory does not complete a true circle, but is, as it
were, a spiral slightly divergent therefrom. It is no longer a perfectly
circulating decimal. Where, on the other hand, there is no memory of a
like present, where, in fact, the memory is not, so to speak, spiral,
there is no accumulation of improvement. The effect of any variation is
not transmitted, and is not thus pregnant of still further change.

As regards the second of the two classes of actions above referred
to--those, namely which are not recurrent or habitual, _and at no point
of which is there a memory of a past present like the one which is
present now_--there will have been no accumulation of strong and well-
knit memory as regards the action as a whole, but action, if taken at
all, will be taken upon disjointed fragments of individual actions (our
own and those of other people) pieced together with a result more or less
satisfactory according to circumstances.

But it does not follow that the action of two people who have had
tolerably similar antecedents and are placed in tolerably similar
circumstances should be more unlike each other in this second case than
in the first. On the contrary, nothing is more common than to observe
the same kind of people making the same kind of mistake when placed for
the first time in the same kind of new circumstances. I did not say that
there would be no sameness of action without memory of a like present.
There may be sameness of action proceeding from a memory, conscious or
unconscious, of like antecedents, and _a presence only of like presents
without recollection of the same_.

The sameness of action of like persons placed under like circumstances
for the first time, resembles the sameness of action of inorganic matter
under the same combinations. Let us for a moment suppose what we call
non-living substances to be capable of remembering their antecedents, and
that the changes they undergo are the expressions